Understand Architectural Window Film Inspection Standards

Architectural Visual Inspection Guidelines For Applied Window Film

 1. Installed film on flat glass surfaces is not expected to have the same level of visual

 quality as glass. The following criteria apply to the installed film only and not to any defect

 inherent in the glass.

 2. Installed film has a discrete time for full adhesion to be affected since installation utilizes

 a detergent solution in the water to float the film onto the glass: the excess water is

 squeegeed out, but inevitably residual water will remain between the film and glass. The

 time to achieve full adhesion is often referred to as “the adhesive cure time”. Adhesion will

 be increasing from a lower value during this time. Visual and adhesive cure time is related

 to thickness of the film and various metallic coatings on the film. Typical visual cure times

 may be extended or shortened according to climatic conditions.

 3. Inspection for optical quality can be made before full visual cure is attained. Table

 provides a guide for typical visual cure times. It should be noted that effects during cure,

 such as water bubbles, water distortion, and water haze are not to be regarded as defects.

 4. The glass with applied film shall be viewed at right angles to the glass from the room

 side, at a distance of not less than 6 feet (2 meters). Viewing shall be carried out in natural

 daylight, not in direct sunlight, and shall assess the normal vision area with the exception of

 a 2 inch (50mm) wide band around the perimeter of the unit.

 5. The installation shall be deemed acceptable if all of the following are unobtrusive (effects

 during visual cure should be disregarded): Dirt Particles, Hair and Fibers, Adhesive Gels,

 Fingerprints, Air Bubbles, Water Haze, Scores and Scratches, Film Distortion, Creases,

 Edge Lift, Nicks and Tears. Inspection may be made within 1 day of installation.

 Obtrusiveness of blemishes shall be judged by looking through the film installation under

 lighting conditions described in 4.

 6. The 2 inch (50mm) wide band around the perimeter shall be assessed by a similar

 procedure to that in 3 and 4, but a small number of particles is considered acceptable

 where poor frame condition mitigates against the high quality standards normally achieved.

 7. Edge gaps will normally be 1/32

–

 1/16 inch (1-4 mm). This allows for the water used in

 the installation to be squeegeed out. This ensures that film edges are not raised up by

 contact with the frame margin. Contact with the frame margin could lead to peeling of the

 film.

8. For thicker safety films the edge gaps will normally be 1/32

–

 1/16 inch (1-4 mm), with

 1/32

–

 1/8 inch (1-5mm) being acceptable for films of (7 mil (175)). Combination solar

 control safety films will also fall within this standard. An edge gap of up to 1/16 inch (2mm)

 is recommended, especially for darker (tinted, metallized, tinted/metallized, and sputtered)

 films, to minimize the light line around the edge of the installed film.

 9. Splicing of films is necessary when larger panels of glass are treated, where both length

 and width of the glass exceed the maximum width of film. The splice line itself should not

 be viewed as a defect. This line should be straight and should be parallel to one edge of

 the frame margin. The two pieces of film may be butt joined. The maximum gap at any

 point in the splice line should be 1/64 inch (1mm). Film may be overlapped, spliced or butt

 jointed.

 10. Certain films with special high performance coating may have lengthened cure times.

 Consult the manufacturer for cure times of these films.

 Table 1 – Typical Cure Times

 Film Thickness (mils)          Film Thickness (microns, µ)        Typical Cure Time (days)

 Up to 4 mil                            Up to 100 microns                                                                30 days

 4 to 8 mil                               100 to 200 microns                                                               60 days

 8 to 12 mil                             200 to 300 microns                                                               90 days

 Over 12 but not more than17 mil  Over 300 but not more than425 microns         140 days

 

*Special adaptation of information received from the Glass and Glazing Federation;

 reproduced with their permission .

For more information please visit the International Window Film Association website at: https://iwfa.com/